A conventional wireless device such as a cellular telephone uses either a whip or helical antenna that extends from the top of the cellular telephone. The whip and helical antennas are easily broken off if the cellular telephone is mishandled, for example, by dropping it. Thus, an internal antenna such as a planar inverted F antenna (PIFA), a dual L antenna, and a micro-strip antenna may be disposed within the cellular telephone. Further, the wireless device is often used in close proximity to a human body. Typically, the cellular telephone is held in the hand and next to the ear of the user. However, this may cause potential degradation in the performance of the cellular telephone. That is, transmitted signals may be lost and the efficiency of the antenna to respond to incoming signals may be low.
Low efficiency resulting from user absorption may be mitigated by using a conducting surface such as a ground plane to separate a radiating element and a user's body. Although a single ground PIFA is typically used millimeter wave applications, it may used as an internal antenna with a cellular telephone to reduce degradation in performance in the presence of a human body. In particular, the PIFA may include a ground plane for tuning frequency and bandwidth. However, frequency and bandwidth of the PIFA may be compromised because the ground plane may only tune either the frequency or the bandwidth at a time. Even though the bandwidth may be increased, the size of the internal antenna (e.g., thickness) may also need to be increased to do so, which in turn, may increase the size of cellular telephones. Because of the inherently small size of cellular telephones, the bandwidth of the PIFA may be narrow, which in turn, results in results poor radiating performance. Therefore, a need exist for an improvement in control of the frequency and the bandwidth of an antenna without comprising the size of the antenna.